re-work the simulation time loop in order to support fixed constraints. still wip

This commit is contained in:
jingyuc 2021-07-30 02:08:27 -04:00
parent 5d17353269
commit a37d23fa24
7 changed files with 201 additions and 111 deletions

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@ -95,9 +95,9 @@ public:
btReducedSoftBody* rsb = static_cast<btReducedSoftBody*>(static_cast<btDeformableMultiBodyDynamicsWorld*>(m_dynamicsWorld)->getSoftBodyArray()[0]); btReducedSoftBody* rsb = static_cast<btReducedSoftBody*>(static_cast<btDeformableMultiBodyDynamicsWorld*>(m_dynamicsWorld)->getSoftBodyArray()[0]);
if (first_step /* && !rsb->m_bUpdateRtCst*/) if (first_step /* && !rsb->m_bUpdateRtCst*/)
{ {
// getDeformedShape(rsb, 0, 0.5); getDeformedShape(rsb, 0, 0.5);
first_step = false; first_step = false;
rsb->updateReducedDofs(); rsb->mapToReducedDofs();
} }
float internalTimeStep = 1. / 60.f; float internalTimeStep = 1. / 60.f;
@ -138,7 +138,7 @@ void BasicTest::initPhysics()
m_broadphase = new btDbvtBroadphase(); m_broadphase = new btDbvtBroadphase();
btReducedSoftBodySolver* reducedSoftBodySolver = new btReducedSoftBodySolver(); btReducedSoftBodySolver* reducedSoftBodySolver = new btReducedSoftBodySolver();
reducedSoftBodySolver->setDamping(damping_alpha, damping_beta); reducedSoftBodySolver->setDamping(damping_alpha, damping_beta);
btVector3 gravity = btVector3(0, -9.8, 0); btVector3 gravity = btVector3(0, 0, 0);
reducedSoftBodySolver->setGravity(gravity); reducedSoftBodySolver->setGravity(gravity);
btDeformableMultiBodyConstraintSolver* sol = new btDeformableMultiBodyConstraintSolver(); btDeformableMultiBodyConstraintSolver* sol = new btDeformableMultiBodyConstraintSolver();
@ -164,7 +164,7 @@ void BasicTest::initPhysics()
rsb->translate(btVector3(0, 4, 0)); //TODO: add back translate and scale rsb->translate(btVector3(0, 4, 0)); //TODO: add back translate and scale
// rsb->setTotalMass(0.5); // rsb->setTotalMass(0.5);
rsb->setStiffnessScale(1); rsb->setStiffnessScale(1);
// rsb->setFixedNodes(); rsb->setFixedNodes();
rsb->m_cfg.kKHR = 1; // collision hardness with kinematic objects rsb->m_cfg.kKHR = 1; // collision hardness with kinematic objects
rsb->m_cfg.kCHR = 1; // collision hardness with rigid body rsb->m_cfg.kCHR = 1; // collision hardness with rigid body
rsb->m_cfg.kDF = 0; rsb->m_cfg.kDF = 0;
@ -175,7 +175,7 @@ void BasicTest::initPhysics()
// rsb->setVelocity(btVector3(0, -COLLIDING_VELOCITY, 0)); // rsb->setVelocity(btVector3(0, -COLLIDING_VELOCITY, 0));
// rsb->setRigidVelocity(btVector3(0, 1, 0)); // rsb->setRigidVelocity(btVector3(0, 1, 0));
rsb->setRigidAngularVelocity(btVector3(10, 0, 0)); // rsb->setRigidAngularVelocity(btVector3(1, 0, 0));
// btDeformableGravityForce* gravity_force = new btDeformableGravityForce(gravity); // btDeformableGravityForce* gravity_force = new btDeformableGravityForce(gravity);
// getDeformableDynamicsWorld()->addForce(rsb, gravity_force); // getDeformableDynamicsWorld()->addForce(rsb, gravity_force);

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@ -34,7 +34,9 @@ void btReducedSoftBody::setReducedModes(int start_mode, int num_modes, int full_
m_nFull = full_size; m_nFull = full_size;
m_reducedDofs.resize(m_nReduced, 0); m_reducedDofs.resize(m_nReduced, 0);
m_reducedVelocity.resize(m_nReduced, 0); m_reducedVelocity.resize(m_nReduced, 0);
m_reducedForce.resize(m_nReduced, 0);
m_nodalMass.resize(full_size, 0); m_nodalMass.resize(full_size, 0);
endOfTimeStepZeroing();
} }
void btReducedSoftBody::setMassProps(const tDenseArray& mass_array) void btReducedSoftBody::setMassProps(const tDenseArray& mass_array)
@ -95,12 +97,20 @@ void btReducedSoftBody::setFixedNodes()
m_fixedNodes.push_back(0); m_fixedNodes.push_back(0);
} }
void btReducedSoftBody::endOfTimeStepZeroing()
{
for (int i = 0; i < m_nReduced; ++i)
{
m_reducedForce[i] = 0;
}
}
void btReducedSoftBody::predictIntegratedTransform(btScalar timeStep, btTransform& predictedTransform) void btReducedSoftBody::predictIntegratedTransform(btScalar timeStep, btTransform& predictedTransform)
{ {
btTransformUtil::integrateTransform(m_rigidTransformWorld, m_linearVelocity, m_angularVelocity, timeStep, predictedTransform); btTransformUtil::integrateTransform(m_rigidTransformWorld, m_linearVelocity, m_angularVelocity, timeStep, predictedTransform);
} }
void btReducedSoftBody::updateReducedDofs() void btReducedSoftBody::mapToReducedDofs()
{ {
btAssert(m_reducedDofs.size() == m_nReduced); btAssert(m_reducedDofs.size() == m_nReduced);
for (int j = 0; j < m_nReduced; ++j) for (int j = 0; j < m_nReduced; ++j)
@ -117,7 +127,23 @@ void btReducedSoftBody::updateReducedDofs()
} }
} }
void btReducedSoftBody::updateFullDofs() void btReducedSoftBody::updateReducedDofs(btScalar solverdt)
{
for (int r = 0; r < m_nReduced; ++r)
{
m_reducedDofs[r] += solverdt * m_reducedVelocity[r];
}
}
void btReducedSoftBody::updateFullDofs(btScalar solverdt)
{
for (int i = 0; i < m_nFull; ++i)
{
m_nodes[i].m_x += solverdt * m_nodes[i].m_v;
}
}
void btReducedSoftBody::mapToFullDofs()
{ {
btAssert(m_nodes.size() == m_nFull); btAssert(m_nodes.size() == m_nFull);
TVStack delta_x; TVStack delta_x;
@ -141,6 +167,51 @@ void btReducedSoftBody::updateFullDofs()
} }
} }
void btReducedSoftBody::updateReducedVelocity(btScalar solverdt)
{
// update reduced velocity
for (int r = 0; r < m_nReduced; ++r)
{
btScalar mass_inv = (m_Mr[r] == 0) ? 0 : 1.0 / m_Mr[r]; // TODO: this might be redundant, because Mr is identity
btScalar delta_v = solverdt * mass_inv * m_reducedForce[r];
m_reducedVelocity[r] -= delta_v; //! check this
}
}
void btReducedSoftBody::updateFullVelocity(btScalar solverdt)
{
TVStack v_from_reduced;
v_from_reduced.resize(m_nFull);
// btVector3 current_com = m_rigidTransformWorld.getOrigin() - m_initialOrigin;
for (int i = 0; i < m_nFull; ++i)
{
btVector3 r = m_nodes[i].m_x - m_rigidTransformWorld.getOrigin();
// compute velocity contributed by the reduced velocity
for (int k = 0; k < 3; ++k)
{
v_from_reduced[i][k] = 0;
for (int r = 0; r < m_nReduced; ++r)
{
v_from_reduced[i][k] += m_modes[r][3 * i + k] * m_reducedVelocity[r];
}
}
// get new velocity
m_nodes[i].m_v = m_angularVelocity.cross(r) +
m_rigidTransformWorld.getBasis() * v_from_reduced[i] +
m_linearVelocity;
}
}
void btReducedSoftBody::updateMeshNodePositions(btScalar solverdt)
{
for (int i = 0; i < m_nFull; ++i)
{
m_nodes[i].m_x = solverdt * m_nodes[i].m_v;
}
}
void btReducedSoftBody::proceedToTransform(const btTransform& newTrans) void btReducedSoftBody::proceedToTransform(const btTransform& newTrans)
{ {
setCenterOfMassTransform(newTrans); setCenterOfMassTransform(newTrans);
@ -215,19 +286,29 @@ void btReducedSoftBody::applyImpulse(const btVector3& impulse, const btVector3&
} }
} }
void btReducedSoftBody::applyFullSpaceImpulse(const btVector3& target_vel, int n_node, btScalar dt, tDenseArray& reduced_force) void btReducedSoftBody::applyFullSpaceImpulse(const btVector3& target_vel, int n_node, btScalar dt)
{ {
// zero the reduced force vector
endOfTimeStepZeroing();
// impulse leads to the deformation in the reduced space // impulse leads to the deformation in the reduced space
btVector3 impulse = m_nodalMass[n_node] / dt * (target_vel - m_nodes[n_node].m_v); btVector3 impulse = m_nodalMass[n_node] / dt * (target_vel - m_nodes[n_node].m_v);
for (int i = 0; i < m_nReduced; ++i) for (int i = 0; i < m_nReduced; ++i)
{ {
for (int k = 0; k < 3; ++k) for (int k = 0; k < 3; ++k)
{ {
reduced_force[i] += m_modes[i][3 * n_node + k] * impulse[k]; m_reducedForce[i] = m_modes[i][3 * n_node + k] * impulse[k];
} }
} }
// impulse causes rigid motion // impulse causes rigid motion
applyImpulse(impulse, m_nodes[n_node].m_x); applyImpulse(impulse, m_nodes[n_node].m_x);
// apply impulse to the reduced velocity
updateReducedVelocity(dt);
// apply impulse force, update velocity
updateFullVelocity(dt);
} }
void btReducedSoftBody::applyRigidGravity(const btVector3& gravity, btScalar dt) void btReducedSoftBody::applyRigidGravity(const btVector3& gravity, btScalar dt)
@ -235,27 +316,27 @@ void btReducedSoftBody::applyRigidGravity(const btVector3& gravity, btScalar dt)
// update rigid frame velocity // update rigid frame velocity
m_linearVelocity += dt * gravity; m_linearVelocity += dt * gravity;
// update nodal velocity // // update nodal velocity
for (int i = 0; i < m_nFull; ++i) // for (int i = 0; i < m_nFull; ++i)
{ // {
m_nodes[i].m_v = m_nodes[i].m_v + dt * gravity; // m_nodes[i].m_v += dt * gravity;
} // }
} }
void btReducedSoftBody::applyReducedInternalForce(tDenseArray& reduced_force, const btScalar damping_alpha, const btScalar damping_beta) void btReducedSoftBody::applyReducedInternalForce(const btScalar damping_alpha, const btScalar damping_beta)
{ {
for (int r = 0; r < m_nReduced; ++r) for (int r = 0; r < m_nReduced; ++r)
{ {
reduced_force[r] += m_ksScale * m_Kr[r] * (m_reducedDofs[r] + damping_beta * m_reducedVelocity[r]); m_reducedForce[r] += m_ksScale * m_Kr[r] * (m_reducedDofs[r] + damping_beta * m_reducedVelocity[r]);
} }
} }
void btReducedSoftBody::applyFixedContraints(btScalar dt, tDenseArray& reduced_force) void btReducedSoftBody::applyFixedContraints(btScalar dt)
{ {
for (int n = 0; n < m_fixedNodes.size(); ++n) for (int n = 0; n < m_fixedNodes.size(); ++n)
{ {
// std::cout << reduced_force[0] << "\t" << reduced_force[1] << "\n"; // std::cout << reduced_force[0] << "\t" << reduced_force[1] << "\n";
applyFullSpaceImpulse(btVector3(0, 0, 0), m_fixedNodes[n], dt, reduced_force); applyFullSpaceImpulse(btVector3(0, 0, 0), m_fixedNodes[n], dt);
// std::cout << reduced_force[0] << "\t" << reduced_force[1] << "\n"; // std::cout << reduced_force[0] << "\t" << reduced_force[1] << "\n";
} }
} }

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@ -49,6 +49,7 @@ class btReducedSoftBody : public btSoftBody
tDenseMatrix m_modes; // modes of the reduced deformable model. Each inner array is a mode, outer array size = n_modes tDenseMatrix m_modes; // modes of the reduced deformable model. Each inner array is a mode, outer array size = n_modes
tDenseArray m_reducedDofs; // Reduced degree of freedom tDenseArray m_reducedDofs; // Reduced degree of freedom
tDenseArray m_reducedVelocity; // Reduced velocity array tDenseArray m_reducedVelocity; // Reduced velocity array
tDenseArray m_reducedForce; // reduced force
tDenseArray m_eigenvalues; // eigenvalues of the reduce deformable model tDenseArray m_eigenvalues; // eigenvalues of the reduce deformable model
tDenseArray m_Kr; // reduced stiffness matrix tDenseArray m_Kr; // reduced stiffness matrix
tDenseArray m_Mr; // reduced mass matrix //TODO: do we need this? tDenseArray m_Mr; // reduced mass matrix //TODO: do we need this?
@ -89,15 +90,32 @@ class btReducedSoftBody : public btSoftBody
void predictIntegratedTransform(btScalar step, btTransform& predictedTransform); void predictIntegratedTransform(btScalar step, btTransform& predictedTransform);
void endOfTimeStepZeroing();
// //
// reduced dof related // reduced dof related
// //
// compute reduced degree of freedoms // compute reduced degree of freedoms
void updateReducedDofs(); void updateReducedDofs(btScalar solverdt);
// map to reduced degree of freedoms
void mapToReducedDofs();
// compute full degree of freedoms // compute full degree of freedoms
void updateFullDofs(); void updateFullDofs(btScalar solverdt);
// map to full degree of freedoms
void mapToFullDofs();
// compute reduced velocity update
void updateReducedVelocity(btScalar solverdt);
// compute full space velocity from the reduced velocity
void updateFullVelocity(btScalar solverdt);
// update the full space mesh positions
void updateMeshNodePositions(btScalar solverdt);
// //
// rigid motion related // rigid motion related
@ -110,16 +128,16 @@ class btReducedSoftBody : public btSoftBody
void applyImpulse(const btVector3& impulse, const btVector3& rel_pos); void applyImpulse(const btVector3& impulse, const btVector3& rel_pos);
// apply impulse to nodes in the full space // apply impulse to nodes in the full space
void applyFullSpaceImpulse(const btVector3& target_vel, int n_node, btScalar dt, tDenseArray& reduced_force); void applyFullSpaceImpulse(const btVector3& target_vel, int n_node, btScalar dt);
// apply fixed contraints to the nodes // apply fixed contraints to the nodes
void applyFixedContraints(btScalar dt, tDenseArray& reduced_force); void applyFixedContraints(btScalar dt);
// apply gravity to the rigid frame // apply gravity to the rigid frame
void applyRigidGravity(const btVector3& gravity, btScalar dt); void applyRigidGravity(const btVector3& gravity, btScalar dt);
// apply reduced force // apply reduced force
void applyReducedInternalForce(tDenseArray& reduced_force, const btScalar damping_alpha, const btScalar damping_beta); void applyReducedInternalForce(const btScalar damping_alpha, const btScalar damping_beta);
void proceedToTransform(const btTransform& newTrans); void proceedToTransform(const btTransform& newTrans);

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@ -21,93 +21,70 @@ void btReducedSoftBodySolver::setGravity(const btVector3& gravity)
void btReducedSoftBodySolver::predictMotion(btScalar solverdt) void btReducedSoftBodySolver::predictMotion(btScalar solverdt)
{ {
applyExplicitForce(); applyExplicitForce(solverdt);
// predict new mesh location
predictReduceDeformableMotion(solverdt);
} }
void btReducedSoftBodySolver::applyForce() void btReducedSoftBodySolver::predictReduceDeformableMotion(btScalar solverdt)
{ {
for (int i = 0; i < m_softBodies.size(); ++i) for (int i = 0; i < m_softBodies.size(); ++i)
{ {
btReducedSoftBody* rsb = static_cast<btReducedSoftBody*>(m_softBodies[i]); btReducedSoftBody* rsb = static_cast<btReducedSoftBody*>(m_softBodies[i]);
// get reduced force rsb->updateReducedVelocity(solverdt);
btAlignedObjectArray<btScalar> reduced_force;
reduced_force.resize(rsb->m_reducedDofs.size(), 0); // map reduced velocity to full space velocity
rsb->updateFullVelocity(solverdt);
// update mesh nodal position
// rsb->updateMeshNodePositions(solverdt);
}
}
void btReducedSoftBodySolver::applyExplicitForce(btScalar solverdt)
{
for (int i = 0; i < m_softBodies.size(); ++i)
{
btReducedSoftBody* rsb = static_cast<btReducedSoftBody*>(m_softBodies[i]);
// apply gravity to the rigid frame
rsb->applyRigidGravity(m_gravity, solverdt);
// add internal force (elastic force & damping force) // add internal force (elastic force & damping force)
rsb->applyReducedInternalForce(reduced_force, m_dampingAlpha, m_dampingBeta); rsb->applyReducedInternalForce(m_dampingAlpha, m_dampingBeta);
// apply impulses to reduced deformable objects
static btScalar sim_time = 0;
static int apply_impulse = 0;
// if (rsb->m_reducedModel && apply_impulse < 4)
// {
// if (sim_time > 1 && apply_impulse == 0)
// {
// rsb->applyFullSpaceImpulse(btVector3(0, 1, 0), 0, 2.0 * m_dt, reduced_force);
// apply_impulse++;
// }
// if (sim_time > 2 && apply_impulse == 1)
// {
// rsb->applyFullSpaceImpulse(btVector3(0, -1.2, 0), 0, m_dt, reduced_force);
// apply_impulse++;
// }
// if (sim_time > 3 && apply_impulse == 2)
// {
// rsb->applyFullSpaceImpulse(btVector3(1.1, 0, 0), 0, m_dt, reduced_force);
// apply_impulse++;
// }
// if (sim_time > 4 && apply_impulse == 3)
// {
// rsb->applyFullSpaceImpulse(btVector3(-1, 0, 0), 0, 2.0 * m_dt, reduced_force);
// apply_impulse++;
// }
// }
// apply fixed contraints
// rsb->applyFixedContraints(m_dt, reduced_force); //TODO: solver iteratively with other constraints
// update reduced velocity
for (int r = 0; r < rsb->m_reducedDofs.size(); ++r)
{
btScalar mass_inv = (rsb->m_Mr[r] == 0) ? 0 : 1.0 / rsb->m_Mr[r];
btScalar delta_v = m_dt * mass_inv * reduced_force[r];
rsb->m_reducedVelocity[r] -= delta_v;
}
} }
} }
void btReducedSoftBodySolver::applyExplicitForce()
{
// apply gravity to the rigid frame
for (int i = 0; i < m_softBodies.size(); ++i)
{
btReducedSoftBody* rsb = static_cast<btReducedSoftBody*>(m_softBodies[i]);
rsb->applyRigidGravity(m_gravity, m_dt);
}
// apply internal forces and impulses
applyForce();
}
void btReducedSoftBodySolver::applyTransforms(btScalar timeStep) void btReducedSoftBodySolver::applyTransforms(btScalar timeStep)
{ {
for (int i = 0; i < m_softBodies.size(); ++i) for (int i = 0; i < m_softBodies.size(); ++i)
{ {
btReducedSoftBody* rsb = static_cast<btReducedSoftBody*>(m_softBodies[i]); btReducedSoftBody* rsb = static_cast<btReducedSoftBody*>(m_softBodies[i]);
for (int r = 0; r < rsb->m_reducedDofs.size(); ++r) // update reduced dofs for the next time step
rsb->m_reducedDofs[r] += timeStep * rsb->m_reducedVelocity[r]; rsb->updateReducedDofs(timeStep);
// rigid motion // rigid motion
btTransform predictedTrans; btTransform predictedTrans;
rsb->predictIntegratedTransform(timeStep, predictedTrans); rsb->predictIntegratedTransform(timeStep, predictedTrans);
// std::cout << predictedTrans.getOrigin()[0] << '\t' << predictedTrans.getOrigin()[1] << '\t' << predictedTrans.getOrigin()[2] << '\n';
rsb->proceedToTransform(predictedTrans); rsb->proceedToTransform(predictedTrans);
// std::cout << rsb->getWorldTransform().getOrigin()[0] << '\t' << rsb->getWorldTransform().getOrigin()[1] << '\t' << rsb->getWorldTransform().getOrigin()[2] << '\n';
// std::cout << "----------\n";
// map reduced dof back to full space // update mesh nodal positions for the next time step
rsb->updateFullDofs(); rsb->updateFullDofs(timeStep);
// end of time step clean up
rsb->endOfTimeStepZeroing();
} }
}
void btReducedSoftBodySolver::solveConstraints(btScalar timeStep)
{
// for (int i = 0; i < m_softBodies.size(); ++i)
// {
// btReducedSoftBody* rsb = static_cast<btReducedSoftBody*>(m_softBodies[i]);
// rsb->applyFixedContraints(timeStep);
// }
} }

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@ -14,7 +14,9 @@ class btReducedSoftBodySolver : public btDeformableBodySolver
btVector3 m_gravity; btVector3 m_gravity;
void applyForce(); void predictReduceDeformableMotion(btScalar solverdt);
void applyExplicitForce(btScalar solverdt);
public: public:
btReducedSoftBodySolver(); btReducedSoftBodySolver();
@ -31,10 +33,17 @@ class btReducedSoftBodySolver : public btDeformableBodySolver
virtual void predictMotion(btScalar solverdt); virtual void predictMotion(btScalar solverdt);
virtual void applyExplicitForce();
virtual void applyTransforms(btScalar timeStep); virtual void applyTransforms(btScalar timeStep);
virtual void solveConstraints(btScalar timeStep);
// virtual void setProjection() {}
// virtual void setLagrangeMultiplier() {}
// virtual void setupDeformableSolve(bool implicit);
// virtual void solveDeformableConstraints(btScalar solverdt);
}; };
#endif // BT_REDUCED_SOFT_BODY_DYNAMICS_WORLD_H #endif // BT_REDUCED_SOFT_BODY_DYNAMICS_WORLD_H

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@ -85,7 +85,7 @@ public:
void backupVelocity(); void backupVelocity();
// set m_dv and m_backupVelocity to desired value to prepare for momentum solve // set m_dv and m_backupVelocity to desired value to prepare for momentum solve
void setupDeformableSolve(bool implicit); virtual void setupDeformableSolve(bool implicit);
// set the current velocity to that backed up in m_backupVelocity // set the current velocity to that backed up in m_backupVelocity
void revertVelocity(); void revertVelocity();
@ -199,9 +199,11 @@ public:
m_objective->m_projection.setLagrangeMultiplier(); m_objective->m_projection.setLagrangeMultiplier();
} }
virtual void solveConstraints(btScalar timeStep) {}
// unused functions // unused functions
virtual void optimize(btAlignedObjectArray<btSoftBody*>& softBodies, bool forceUpdate = false) {} virtual void optimize(btAlignedObjectArray<btSoftBody*>& softBodies, bool forceUpdate = false) {}
virtual void solveConstraints(btScalar dt) {} // virtual void solveConstraints(btScalar dt) {}
virtual bool checkInitialized() { return true; } virtual bool checkInitialized() { return true; }
virtual void copyBackToSoftBodies(bool bMove = true) {} virtual void copyBackToSoftBodies(bool bMove = true) {}
}; };

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@ -302,30 +302,33 @@ void btDeformableMultiBodyDynamicsWorld::integrateTransforms(btScalar timeStep)
void btDeformableMultiBodyDynamicsWorld::solveConstraints(btScalar timeStep) void btDeformableMultiBodyDynamicsWorld::solveConstraints(btScalar timeStep)
{ {
BT_PROFILE("btDeformableMultiBodyDynamicsWorld::solveConstraints"); // BT_PROFILE("btDeformableMultiBodyDynamicsWorld::solveConstraints");
// save v_{n+1}^* velocity after explicit forces // // save v_{n+1}^* velocity after explicit forces
m_deformableBodySolver->backupVelocity(); // m_deformableBodySolver->backupVelocity();
// set up constraints among multibodies and between multibodies and deformable bodies // // set up constraints among multibodies and between multibodies and deformable bodies
setupConstraints(); // setupConstraints();
// solve contact constraints // // solve contact constraints
solveContactConstraints(); // solveContactConstraints();
// set up the directions in which the velocity does not change in the momentum solve // // set up the directions in which the velocity does not change in the momentum solve
if (m_useProjection) // if (m_useProjection)
m_deformableBodySolver->setProjection(); // m_deformableBodySolver->setProjection();
else // else
m_deformableBodySolver->setLagrangeMultiplier(); // m_deformableBodySolver->setLagrangeMultiplier();
// for explicit scheme, m_backupVelocity = v_{n+1}^* // // for explicit scheme, m_backupVelocity = v_{n+1}^*
// for implicit scheme, m_backupVelocity = v_n // // for implicit scheme, m_backupVelocity = v_n
// Here, set dv = v_{n+1} - v_n for nodes in contact // // Here, set dv = v_{n+1} - v_n for nodes in contact
m_deformableBodySolver->setupDeformableSolve(m_implicit); // m_deformableBodySolver->setupDeformableSolve(m_implicit);
// At this point, dv should be golden for nodes in contact // // At this point, dv should be golden for nodes in contact
// proceed to solve deformable momentum equation // // proceed to solve deformable momentum equation
m_deformableBodySolver->solveDeformableConstraints(timeStep); // m_deformableBodySolver->solveDeformableConstraints(timeStep);
// TODO: need better design
m_deformableBodySolver->solveConstraints(timeStep);
} }
void btDeformableMultiBodyDynamicsWorld::setupConstraints() void btDeformableMultiBodyDynamicsWorld::setupConstraints()